129199968 has 96 divisors (see below), whose sum is σ = 379058400. Its totient is φ = 42812928.

The previous prime is 129199951. The next prime is 129199969. The reversal of 129199968 is 869991921.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129199969) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 197530 + ... + 198182.

It is an arithmetic number, because the mean of its divisors is an integer number (3948525).

Almost surely, 2^129199968 is an apocalyptic number.

129199968 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129199968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189529200).

129199968 is an abundant number, since it is smaller than the sum of its proper divisors (249858432).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129199968 is a wasteful number, since it uses less digits than its factorization.

129199968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 901 (or 887 counting only the distinct ones).

The product of its digits is 629856, while the sum is 54.

The square root of 129199968 is about 11366.6163830755. The cubic root of 129199968 is about 505.5383834408.

The spelling of 129199968 in words is "one hundred twenty-nine million, one hundred ninety-nine thousand, nine hundred sixty-eight".